题目

Teddy's bear     The story of how the teddy bear was invented is an interesting one. In 1902, American president Theodore (Teddy) Roosevelt was hunting (打猎) in the forest   41   several of his friends. Almost everyone had successfully shot (射中) an animal, but the president   42   not. Nobody wanted to make the president look   43  , so they tied an American black bear to a   44  . They wanted the president to shoot (射中)  45  .     The president was very surprised to see the bear tied to a tree. He felt it was   46   to shoot the bear, because it c一氧化碳还原氧化铁的装置如图（B中盛有澄清的石灰水），回答问题．（1）写出A中发生反应的化学方程式．______ 2Fe+3CO2